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Global Drylands Center news

Global Drylands Center news

Global Drylands Center news

Post-doctoral Research Opportunity at the Sala Lab

May 20, 2022

The Global Drylands Center (GDC), the Extremes Focal Area and the Sala Lab are seeking a postdoctoral research scholar to lead two types of complementary activities. The postdoctoral research scholar will contribute to synthesis activities within the Global Drylands Center and the Extremes Focal Area in close collaboration with the Director, the Executive Committee and GDC-Extremes members. Synthesis activities will be complemented by the deployment of a field experiment at the Jornada Experimental Range in New Mexico with the objective of understanding interactions between intensity and duration of grazing and drought. The experiment will test the hypothesis that thresholds in rates of grass decline and recovery will be controlled by the interaction of defoliation amount, drought severity, and press duration.

This is a grant-funded position. Continuation is contingent on future grant funding. This position is expected to run for two consecutive years. The second-year renewal is contingent upon satisfactory progress and contribution to the collective program.

Essential duties

  1. Collaborate in the activities of the Global Drylands Center and Extremes Focal Area including synthesis, education and outreach.
  2. Design and deploy field experiment and collect data in collaboration with lab manager and graduate students.
  3. Analyze experimental data and write scientific papers associated with the research.
  4. Travel to meetings to perform the work and present results.
  5. Be an active member in research group activities (e.g., participate in lab meetings, mentor students).

Please use this link for more information and to apply:

Applications are due by June 12 at 3:00 p.m. AZ time.

Applications will continue to be accepted on a rolling basis for a reserve pool. Applications in the reserve pool may then be reviewed in the order in which they were received until the position is filled.

GDC Executive Committee Member Enrique Vivoni’s Latest Publication Explores Brush Management

January 6, 2022

by Celina Osuna

The Global Drylands Center wishes to congratulate Executive Committee Member Enrique R. Vivoni on his latest publication this month in Agricultural and Forest Meteorology, “A micrometeorological flux perspective on brush management in a shrub-encroached Sonoran Desert grassland,” for which he is the first author. Vivoni is a professor in the School of Earth and Space Exploration and the School of Sustainable Engineering and the Built Environment. His research focuses on water, climate and ecosystem processes and interactions with sustainability and management, with a specific emphasis on semiarid and arid regions of North America.

The article is the result of over 7 years of work studying and comparing “ecosystem responses to brush management in an herbicide-treated site to an untreated, control location to explicitly account for pre-treatment differences” in the Santa Rita Experimental Range (SRER) of the Sonoran Desert, just under 30 miles south of Tucson. Its contribution is especially important with regard to brush management strategies, which “rarely account for site differences that might occur prior to treatment.”

Below is the abstract, and you can access the full article here:

Woody plant encroachment typically limits the forage productivity of managed rangelands and alters a panoply of semiarid ecosystem processes and services. Intervention strategies to reduce woody plant abundance, collectively termed “brush management”, often lack observations to quantify and interpret changes in ecosystem processes. Furthermore, comparative studies between treated and untreated areas should account for heterogeneity since plant composition, microclimate, topoedaphic factors, and historical land use can substantially vary over short distances in drylands. Here, we quantify ecosystem responses to brush management after a single aerial herbicide application on an 18 hectare shrub-encroached grassland (savanna) in southern Arizona, USA. We conducted a pre- and post-treatment comparison of a flux tower site in the treated area with that of a tower in a nearby control site. The comparison, spanning a seven year period, included: (1) ground, airborne, and satellite-based measurements of vegetation structure, and (2) eddy covariance measurements. The herbicide treatment defoliated the dominant shrub (velvet mesquite, Prosopis velutina) and led to a temporary reduction in summer greening, but full foliar recovery occurred within two years. Contrary to expectations, perennial grass cover decreased and bare soil cover increased on the treated site. Relative amounts of evapotranspiration were reduced, while carbon uptake increased during the 2 year post-treatment period at the treated site due to a higher water use efficiency in the following spring. During mesquite recovery, carbon uptake was enhanced by higher gross primary productivity and accompanied by a decrease in ecosystem respiration relative to the untreated site. Mesquite recovery was facilitated by access to deep soil water, carbohydrate reserves in rooting systems, and a lower competition from reduced perennial grass cover. 

Scientific American takes interest in ASU drylands research

November 2, 2021

sand dunesGlobal Drylands Center’s Osvaldo Sala and Celina Osuna collaborated with Ed Finn, Director of ASU’s Center for Science and the Imagination (CSI), and co-authored a piece for Scientific American to celebrate the premiere of Dennis Villeneuve’s epic adaptation of Dune and take the opportunity to shed light on the beauty and biodiversity of the earth’s deserts in the face of common misrepresentations.

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GDC founding director appointed to NASEM Committee to advise USGCRP

October 15, 2021

In July 2021, Osvaldo Sala, founding director of the Global Drylands Center and Julie A. Wrigley Chair, Regents and Foundation Professor, was nominated by the National Academies of Science, Engineering, and Medicine (NASEM) to serve a three-year term on the Committee to Advise the U.S. Global Change Research Program (USGCRP).

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Researchers working to restore desert's vital 'biocrust'

Arizona Republic | December 15, 2020

Ferran Garcia-Pichel, a member of the Global Dryland Center's executive committee board, is one of many researchers volunteering to study and resore biocrust in the McDowell Sonoran Conservancy. This work was the focus of an article in the Arizona Republic, "How researchers hope to preserve and restore 'biocrust,' the desert's protective skin."

Biocrust stabilizes desert soil and protects it from erosion. "If there is no crust, nothing protects the soil. So with any amount of storm or wind, you'll get anything from sun devils to to big haboobs," Garcia-Pichel said in the article. Read more about biocrust and its importance in the Arizona Republic.

GDC executive board member Ferran Garcia-Pichel named Regents Professor

ASU Now | November 23, 2020

Ferran Garcia-Pichel, the Virginia M. Ullman Professor of the Environment in the School of Life Sciences, is one of four new Regents Professors at Arizona State University. Garcia-Pinchel is on the executive committee of the Global Drylands Center.

Garcia-Pichel's discoveries on the roles that microbes play in the environment are considered pioneering and transdisciplinary in his field. His research has enabled convergence of different disciplines combining approaches from biogeochemistry, geomicrobiology and global-change biology, thus opening up new frontiers of research. His research provided much of the most important knowledge of microbial ecology including the ecological and genetic diversity of the cyanobacteria, perhaps the most essential bacteria on the planet. His discoveries are shaping our understanding of the deep history of Earth from deserts to oceans. Ecological research is only beginning to come to grips with some of Garcia-Pichel's newest discoveries.

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Con Ciencia en las Américas seminar series

November 20, 2020

Watch a new Spanish language seminar series, Con Ciencia En Las Américas, organized by early-career researchers at Stanford University and the University of Santiago in Chile. The goal of Con Ciencia En Las Américas is to highlight Latin American scholars, create a broader community of scholars across the Americas, and provide Spanish language science content for a broad audience.

In this episode from October 28, 2020, Osvaldo Sala talks to Esteban Jobbágy and moderator Guadalupe Carrillo about the topic: "From forests to agricultural land: How human intervention affects the biodiversity of arid and semi-arid ecosystems."

ASU professor receives prestigious award for mentoring, interdisciplinary research

September 24, 2020

Man wearing lab coat looks into microscopeFerran Garcia-Pichel, Arizona State University professor and researcher, has been awarded the 2021 D.C. White Award by the American Society for Microbiology.

The American Society for Microbiology is one of the largest professional societies dedicated to the life sciences and is composed of 30,000 scientists and health practitioners.

The award recognizes distinguished accomplishments in both interdisciplinary research and mentoring. It was created in honor of David C. White, a well-known microbial ecologist widely recognized as a leader in interdisciplinary science, and for his dedicated and inspiring work as a mentor and teacher.

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New study shows soil as significant carbon sequestration driver

ASU Now | September 17, 2020

rich soil with single sprout illuminated in sunlightAs harmful atmospheric carbon dioxide levels continue to increase, understanding the planetary carbon balance has become the single most important scientific question.

A new report by two leading ecological scientists at Arizona State University quantified the global soil carbon sequestered by roots plus the amount leached into the soil. They revealed that climate and land-use are major influencers of belowground carbon sequestration. The study, “Global patterns and climatic controls of belowground net carbon fixation,” also found that the amount of carbon sequestered belowground changes with precipitation but its effect varies among large vegetation types.

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Vegetation shifts can outweigh climate change in desert rangelands

ASU Now | May 18, 2020

Grasslands across the globe, which support the majority of the world’s grazing animals, have been transitioning to shrub lands in a process that scientists call “woody plant encroachment.”

Managed grazing of drylands is the most extensive form of land use on the planet, which has led to widespread efforts to reverse this trend and restore grass cover.

Until now, researchers have thought that because woody plants like trees and shrubs have deeper roots than grass, woody plant encroachment resulted in less water entering streams and groundwater aquifers. This was because scientists typically studied the effect the grassland shift toward shrubs has on water resources on flat ground.

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Global Drylands Center honors Professor Paul Hirt

April 15, 2020

Portrait of Paul HirtThe Global Drylands Center honors Professor Paul Hirt’s service as a member of the GDC Executive Board since its inception in 2017. Following 33 years of his academic career, with 16 of those years at Arizona State University, Professor Hirt will be retiring at the end of the Spring 2020 semester.

Paul Hirt is a historian specializing in the American West, environmental history, environmental policy and sustainability studies. Hirt's publications include a monograph on the history of electric power in the U.S. Northwest and British Columbia, titled "The Wired Northwest" (Univ Press of Kansas, 2012). He also published a history of national forest management since WWII ("A Conspiracy of Optimism," 1994), and edited two collections of essays on Northwest history ("Terra Pacifica," 1998 and "Northwest Lands, Northwest Peoples," 1999). Hirt has also authored more than two dozen articles and book chapters on environmental and western history and policy. His current research projects include collaborative interdisciplinary research on energy transitions, water use and conservation, urban growth and sustainability in southern Arizona, and adaptive management in the Colorado River Basin.

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COVID-19: The ultimate stress test for our global futures

March 31, 2020

In response to the COVID-19 virus that has made a sudden, profound global impact, Dr. Osvaldo Sala along with other scholars within the Global Futures Laboratory at Arizona State University have co-authored their most recent article "COVID-19: The Ultimate Stress Test for Our Global Futures." This article details the catastrophic consequences from lack of preparedness of the COVID-19 pandemic and provides solutions on how to effectively move forward from this crisis and how to minimize the devastating effects from future outbreaks.

Global Drylands Center annual newsletter

December 13, 2019

The Global Drylands Center recently published its annual newsletter. The newsletter contains important and exciting news about a recent trip with Global Drylands Center associates to the Jornada Experimental Station in Las Cruces, New Mexico. The purpose of this trip was to highlight research and educational activities of the Global Drylands Center. Specifically, we demonstrated rainfall manipulation experiments and discussed in the field major research findings. Regarding educational activities, we met with Stephanie Bestelmeyer who is the Director of the Asombro Institute for Science Education, which is a leader institution in the field of informal environmental education.

Learn more details and other opportunities within the 2019 Global Drylands Center Annual Newsletter (PDF).

How to preserve commodities in the face of climate change

September 26, 2019

Amazon forest fireGlobal outrage over the fires in the Amazon has once again generated a debate about how to take care of our environment. In analyzing the causes of the fires, experts point their fingers at illegal deforestation by individuals and organizations that want to exploit the forest for agriculture, mining and logging.

However, in certain countries such as Argentina, those very same industries (agriculture, mining and logging) are presented as a source of economic salvation. Is it possible to reconcile both worlds or does nature facing a losing battle? 

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New research by ASU professor furthers understanding of dryland litter cycles

September 11, 2019

Heather ThroopArizona State University professor Heather Throop penned a new research article that advances our understanding of dryland litter cycles. Drylands are arid ecosystems characterized by a lack of water. According to the Food and Agriculture Organization of the United Nations, drylands  "have been shaped by a combination of low precipitation, droughts and heat waves."

Litter in this case refers to parts of plants that have detached and fallen to the ground. A litter cycle is then the journey of litter from its location on the ground, its movement by horizontal or vertical vectors (such as water), and its eventual decomposition in the same or a secondary location. The litter decomposition rates in drylands are often underpredicted, resulting in a key knowledge gap that is important to address because litter decomposition has a significant influence on ecosystem properties. 

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ASU professors named 2019 American Geophysical Union Fellows

August 30, 2019

Osvaldo SalaArizona State University professors Osvaldo Sala, a drylands researcher and Regents Professor in the School of Life Sciences, and Meenakshi Wadhwa, a cosmochemistry expert and the new director of ASU's School of Earth and Space Exploration, have been elected to the 2019 class of the American Geophysical Union Fellows. The election is an honor just 0.1% of AGU members in any given year enjoy. To be elected is a recognition of “attaining scientific eminence through achievements in research, as demonstrated by a breakthrough or discovery, innovation in science or the development of methods and instruments, or sustained impact," according to the AGU.

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Sala elected president of the Ecological Society of America

August 17, 2019

Osvaldo SalaOsvaldo Sala, a Regents and Foundation Professor at Arizona State University and a Distinguished Sustainability Scientist in the Julie Ann Wrigley Global Institute of Sustainability, was elected on August 16 as president of the Ecological Society of America. Elected by ESA members during the society’s annual meeting in Louisville, Kentucky, Sala will be president for a one-year term that ends in 2020. He is the first Hispanic person to serve as president in the organization's century-long history.

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When roundworms lose, carbon emissions rise

June 10, 2019

Sala PNAS Nematode Experiment full imageSoil food webs play a key role in supporting grassland ecosystems, which cover about one-quarter of the land on Earth. Climate change poses a threat to these environments, partly because of the uncertainty of extremes in rainfall, which is projected to increase.

To learn more about the effects of these extreme events, a team of soil and plant ecologists, supported by funding from the National Science Foundation, studied nematodes, which play a key role in carbon and nutrient cycling and decomposition in soil.

Principal Investigator Osvaldo Sala is founding director of the Global Drylands Center at Arizona State University. We asked him about the study, out June 10, 2019, in Proceedings of the National Academy of Sciences.

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NSF grant boosts student-driven ecological research

June 7, 2019

Arizona State University Professors Heather Throop and Osvaldo Sala have been awarded an International Research Experiences for Students (IRES) grant from The National Science Foundation of approximately $294,000. The grant, initiated under the auspices of the Global Drylands Center (GDC), will fund ecological research projects led by the collaborative effort of GDC and the Gobabeb Training and Research Center in Namibia.

IRES supports research for U.S. students contributing to the development of a diverse and globally engaged workforce. Student-driven projects will explore how broad-scale climate patterns and local-scale factors (e.g. soil properties) interact to control dryland ecological processes.

GDC map
Distribution of global drylands (delineated by dashed lines) and the number of peer-reviewed studies on dryland ecology by country (modified from Maestre et al. 2012). Namibia is located in the red circle.

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